If you are male you should twice before placing a laptop on your lap - the laptop can raise the temperature inside your testicles by three degrees celcius and seriously lower your sperm count.

Lead researchers, Yefim Sheynkin, State University of New York at Stony Brook, said "Some people don't use laptops on their laps, but a lot of young men, or boys, have all these wireless services and they do use them on their laps to play games or do all sorts of things. This is a continuous heat exposure. In 10 or 20 years, when they try to have a family, they might have problems,"

You can read about this study in the journal Human Reproduction.

Eventually, say the researchers, a habitual male user of laptops could become infertile (if the computer is on his lap every time he uses it).

Dr. Sheynkin said males should place the laptop on a desk. Anywhere, except on the man's or boy's lap.

Male sperm counts in Western countries have been dropping for the last twenty years.